Underbody Aero Panels

[lmoengnr]

exactly what i last said if the top/front of the vehicle dosnt change but u increase airspeed underneath and better transition from the rear u are making better use of the already used drag over the top to now help push vehicle down instead of back or just wasted flow

Its all about 'controlling' the airflow, channeling it through various passages to increase velocity, but it still increases drag...
The team that raced the Daytona Supercars Shelby Daytona replica at the Bathurst 12 Hour had the fastest car in a straight, but it lacked mid corner grip... They added aero, which increased downforce and grip mid corner, but lost 25KMH off the top speed. Lap times were slightly slower as well.

 

[07GTS]

Its all about 'controlling' the airflow, channeling it through various passages to increase velocity, but it still increases drag...
The team that raced the Daytona Supercars Shelby Daytona replica at the Bathurst 12 Hour had the fastest car in a straight, but it lacked mid corner grip... They added aero, which increased downforce and grip mid corner, but lost 25KMH off the top speed. Lap times were slightly slower as well.

this guy finds more downforce with less drag only with flat underbody
https://drivetribe.com/p/how-effect...QlJZSqm3Nh3YIbi8OQ?iid=bIx67ZfDQV-9Ssrvpj0BXg

 

[Hq King]

@Hq King is there any little square rubber plugs along the side of the Ute following the side skirts?

They look like this View attachment 206335

If there is how many is there?

Here is a photo of the passenger's side approximately 1100 mm in front of rear wheel centre there are 2 of them at 220 mm apart on each side could these be where the mounting brackets you have and yes there are the 4 mounting bolt thingies on the fuel tank

 

[Hq King]

Here is a photo of the passenger's side approximately 1100 mm in front of rear wheel centre there are 2 of them at 220 mm apart on each side could these be where the mounting brackets you have and yes there are the 4 mounting bolt thingies on the fuel tank

Ok guys thanks for your imput had a look at long panels and see there is a row of attachment points along the outside edge which the ute does not have so I guess that is a no go for the panels I am glad I found out before getting panels I am not keen on drilling holes etc to fit (at this stage )

 

[mpower]

exactly what i last said if the top/front of the vehicle dosnt change but u increase airspeed underneath and better transition from the rear u are making better use of the already used drag over the top to now help push vehicle down instead of back or just wasted flow

downforce without drag is impossible, that's just physics. changing the flow in and under will reduce drag and have the opposite effect.

here's an article that sums it all up nicely.

https://nasaspeed.news/tech/aero/ai...ases-lap-times-and-isnt-that-the-whole-point/

these panels you are all looking at I can't see that they'd do much of anything unless they are in fact reducing drag by increasing flow, which in turn will theoretically reduce grip and also improve economy. I don't think i'd bother with them myself unless part of an overall change to the aero of the car. so you'd probably want a wing that can give you some downforce back and maybe a front splitter as well.

 

[Mattricho]

@Hq King that sucks about the panels not going to fit but lucky you didn’t buy them first.

I never bought the underbody aero for any drag increase/ decrease or anything like that I got them because I drive down dirt roads that aren’t in the best condition and wanted some protection for the underside of the car.

 

[mpower]

@Hq King that sucks about the panels not going to fit but lucky you didn’t buy them first.

I never bought the underbody aero for any drag increase/ decrease or anything like that I got them because I drive down dirt roads that aren’t in the best condition and wanted some protection for the underside of the car.

as far as I can tell this is the best reason to buy them.

 

[Hq King]

as far as I can tell this is the best reason to buy them.

With the underbody aero you are dealing with what they call ground effect which is completely opposite to a wing Julian Edgar has a book modifying aerodynamics on street cars look him up on you tube
If you smooth out your entire underbody you will get better fuel economy and a measured down force at 100 k plus instead of lift . Well that is my uneducated understanding of it anyway, by no means will the holden aero kit do either ,but my plan was to use the same mounting points /fixtures to fill in the rest of the gaps

 

[Hq King]

@Hq King that sucks about the panels not going to fit but lucky you didn’t buy them first.

I never bought the underbody aero for any drag increase/ decrease or anything like that I got them because I drive down dirt roads that aren’t in the best condition and wanted some protection for the underside of the car.

Hey thanks am pretty guttered was looking forward to installing a complete aero kit just to see if it made any difference ánd just because I can I was not looking for any meaningful improvements but thought it would be cool . I have not given up on the idea completely but it is a definite setback

 

[tommy_z]

Did the Caprice ever get underbody aero appointments? Then the shared platform with the Ute could potentially mean shares components?

At least you can mount the sump guard in place!

@Hq King that sucks about the panels not going to fit but lucky you didn’t buy them first.

I never bought the underbody aero for any drag increase/ decrease or anything like that I got them because I drive down dirt roads that aren’t in the best condition and wanted some protection for the underside of the car.

Yes that was the case for me, especially the sump guard for protecting the engine.

I never drove my Director for a longer distance run without the panels so I can’t give a before and after fuel figure but Holden’s media articles in 2013 did talk about lowering the drag coefficient of the car and the underbody aero panels played a part in it.. it does clean up the underbody for sure and at best a very slight improvement in fuel consumption. Definitely won’t do any harm though.